China’s artificial intelligence-powered face changing app ZAO apologized on Tuesday for controversies caused by its user agreement and pledged to modify the terms, after the app sparked widespread concerns in recent days over the possible abuse of users’ privacy that may favor criminal activities.

“We have been reflecting and revising [our product] these last two days for not being able to address issues that are of core public concern … ZAO will not store personal facial biological-recognition information,” ZAO said in a post on its Weibo account on Tuesday morning, while also vowing to protect personal information and data security comprehensively.

The app, developed by Chinese dating app Momo, allows users to upload their selfies and swap their faces with celebrities in video clips from films and television dramas. It gained popularity over the weekend, but then sparked concerns over how personal data may be used, based on the app’s original user agreement. Some suggest that criminals may use the facial biological-recognition date to commit crimes.

The primary item in the user agreement noted that if a subscriber granted personal information to ZAO, the app could in turn store it and use it for free globally. This could not be withdrawn and had no time limit. The company also has the right to sublicense and re-permission the data, which is not limited to facial photos, pictures, videos, and edited versions of these.

ZAO said on Tuesday that if users delete information or cancel their accounts, the app will delete relevant information based on relevant regulations and rules.

In response to some users’ worries that the app could be misused by individuals to access their online payment accounts by scanning their faces, ZAO stressed that using the app won’t incur any payment risks.

“The face-swapping presented in the video is not your true information, although it looks similar in psychical eyes… We don’t collect any personal biological information,” reads the statement.

This is the second time that ZAO revised its user terms after worries mounted.

On Sunday, the app deleted some items formerly in the user agreement, including the stipulation that subscribers’ portraits could be used freely by the app and could never be withdrawn. It also included a special notice stressing that the agreement is only applicable to face-swapping and will not be used for other purposes.

The app’s rating on Apple’s App Store was 2.7 stars out of five as of 12 am on Tuesday, down from 4.6 stars on Friday.